678 



ACCOUNT OF THE 



inina also appears to be capable of entering into combi- 

 nation with magnesia, so as no longer to be taken up by 

 potash ; and the same earth seems to promote the solution 

 of lime in potash. So that on the whole, the existence of 

 affinities between some of the earths appears to be esta- 

 blished, although not to the extent supposed by MM. 

 Kirwan and Guyton. Mr. Chenevix allows the truth of 

 Mr. BerthoUet's position respecting the effect of masses on 

 chemical affinities, but observes, that this effect is by no 

 means unlimited ; and that the proposition, if true in its 

 full extent, would very much increase the difficulties of 

 chemical analyses, and lessen the important benefits 

 which they confer on the science of mineralogy. 



On the 3d of June, a description of the anatomy of the 

 Ornithorhynchus hy^trix, by Everard Home, Esq. F.R.S. 

 was laid before the Society. 



This animal has been described and figured by Dr. Shaw, 

 under the nume of myrmecophaga aculeata, but from the 

 absence of mammae, and from its greater internal resem- 

 blance to the ornithorhynchus than to the other myrme- 

 Cophagae, Mr. Home chooses to consider it as belonging to 

 the same genus with that singular animal, although he 

 thinks it possible that it may hereiifter be found to require 

 , a distinct generic name. It is a native of New South Wales, 

 and several specimens have been brought over in spirits : 

 its length is about seventeen inches ; it is covered with 

 hair and with quills. Its bill somewhat resembles that of the 

 ornithorhynchus, but wants the lateral lips. Its teeth are 

 horny, and confined to the tongue and the palate: the 

 hind legs are furnished with a spur. The stomach has a 

 number of homy papillae near the pylorus: it is much 

 larger than that ofthe ornithorhynchus paradoxus; and the 

 animal appears to swallow a considerable quantity of ^and 

 with its food. The second branch of the fifth pair of nerves 

 is extremely small, so that this species has probably no pe- 

 culiar sense of feeling in its bill ; that of smell appears to 

 compensate the deficiency. The small bones of the ear are 

 only two, corresponding to the malleus and stapes ; the 

 divisions of the cochlea are cartilaginous. The contents of 

 the pelvis agree with those of the ornithorhynchus, in 

 greatly resembling the class of birds. Mr. Home has exa- 

 mined several other species of manis and myrmecophaga, 

 but finds that they all are furnished with mammae. The 

 peculiar characters of the genus ornithorhynchus appear 

 to be the spur on the hitid legs, the absence of nipples, the 

 smooth beak, and the horny teeth. From all these con- 

 siderations, Mr. Home infers that the genus forms a con- 

 necting-link between the mammalia, avcs, and amphibia. 

 The Society adjourned to the j* th. 



On the 17th an analysis of a pulmonary calculus, by P. 

 Crampton, Esq. was communicated by the Hon G. Knox, 

 F.R.S. 



Mr. Crampton found in lOO parts of the pulmonary cal- 

 culus that he examined, 45 of lime, 37 of carbonic acid, 

 and 1 8 of animal matter and water ; this was probably al- 

 bumen, being coagulable in acids. He thinks it probable 

 that this specimen may have been of a different nature from 

 those which are described by Fourcroy, and which have 

 been supposed to contain phosphate of lime. Mr. Crampton 

 thinks it easier to mrderstand how phosphate of lime might 

 have been separated from the blood, than carbonate; but he 

 conceives that even this maybe deposited in the lungs, by a 

 morbid process, similar to the healthy one, by which it is 

 secreted, to form a considerable part of the bones. 



The same evening a letter from Mr. Carlisle to the presi- 

 dent was read, containing a description of two kinds of eyes 

 observed in the Gryllus gryllotalpa; with other circumstances 

 respecting the structure and natural history of that animal. 



Mr. Carlisle first describes the eyes, commonly so called : 

 he observes that a membrane, which appears under the mi- 

 croscope to be reticulated, and covered with a dark brown 

 opaque, pulpy matter, is applied in immediate contact 

 with all the interior surfaces of the cornea, and that behind 

 this there is a, portion of brain. It appeared, on exposing a 

 section of the head to the direct rays of the sun, that the 

 dark coloured substance intercepted the light almost com- 

 pletely. Mr. Carlisle therefore thinks that these eyes are 

 principally subservient to measuring the intensity of light, 

 and to denoting the, illuminated and shadowed parts of ob- 

 jects. The stemmata, which have a greater resemblance to 

 the eyes of quadrupeds, are two in number, situated in the 

 summit of the head : they are pellucid, brilliant lenses, of 

 a homy substance, J^, of an inch in diameter: under them 

 is found a portion of jelly, and next to this a semiopaqiie 

 membrane, on which the figures of surrounding objects are 

 painted by the lens, and may be discovered by the help of 

 a microscope: behind it is a white mass, connected with 

 the brain, and a branch of the bronchial tubes is so nearly 

 in contact with it, that Mr. Carlisle thinks.it may possibly 

 affect the distance of the membrane, receiving the image, 

 from the lens. The two setaceous projections from the 

 tail of the insect Mr. Carlisle supposes to serve the purpose 

 of antennae, since the insect runs backwards as readily as 

 forwards, and never turns in its burrow : this passage is 

 formed simply by compressing the earth, without throwing 

 anj' out of it. The abdomen of the insect contains a craw, 

 a gizzard, and a digesting stomach ; it appears to live on 

 other insects, chiefly coleopterous. The peculiar noise. 



